CN118743972A - Combined urea synthesis reaction device and system comprising same - Google Patents
Combined urea synthesis reaction device and system comprising same Download PDFInfo
- Publication number
- CN118743972A CN118743972A CN202410437545.2A CN202410437545A CN118743972A CN 118743972 A CN118743972 A CN 118743972A CN 202410437545 A CN202410437545 A CN 202410437545A CN 118743972 A CN118743972 A CN 118743972A
- Authority
- CN
- China
- Prior art keywords
- synthesis reaction
- urea synthesis
- reaction section
- section
- urea
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000003786 synthesis reaction Methods 0.000 title claims abstract description 126
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 title claims abstract description 98
- 239000004202 carbamide Substances 0.000 title claims abstract description 98
- BAVYZALUXZFZLV-UHFFFAOYSA-O Methylammonium ion Chemical compound [NH3+]C BAVYZALUXZFZLV-UHFFFAOYSA-O 0.000 claims abstract description 58
- 238000006243 chemical reaction Methods 0.000 claims abstract description 34
- 238000005406 washing Methods 0.000 claims abstract description 32
- 239000007789 gas Substances 0.000 claims description 54
- 239000007788 liquid Substances 0.000 claims description 37
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 36
- BAVYZALUXZFZLV-UHFFFAOYSA-N Methylamine Chemical compound NC BAVYZALUXZFZLV-UHFFFAOYSA-N 0.000 claims description 22
- 230000015572 biosynthetic process Effects 0.000 claims description 15
- BVCZEBOGSOYJJT-UHFFFAOYSA-N ammonium carbamate Chemical compound [NH4+].NC([O-])=O BVCZEBOGSOYJJT-UHFFFAOYSA-N 0.000 claims description 13
- KXDHJXZQYSOELW-UHFFFAOYSA-N carbonic acid monoamide Natural products NC(O)=O KXDHJXZQYSOELW-UHFFFAOYSA-N 0.000 claims description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 10
- 239000011261 inert gas Substances 0.000 claims description 7
- 238000012856 packing Methods 0.000 claims description 7
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 5
- 210000002700 urine Anatomy 0.000 claims description 5
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 3
- 239000001569 carbon dioxide Substances 0.000 claims description 2
- RTWNYYOXLSILQN-UHFFFAOYSA-N methanediamine Chemical compound NCN RTWNYYOXLSILQN-UHFFFAOYSA-N 0.000 claims description 2
- 239000002994 raw material Substances 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 abstract description 4
- 238000004886 process control Methods 0.000 abstract 1
- 238000000034 method Methods 0.000 description 20
- 239000000463 material Substances 0.000 description 7
- 238000003466 welding Methods 0.000 description 7
- 230000002194 synthesizing effect Effects 0.000 description 6
- 229910021529 ammonia Inorganic materials 0.000 description 4
- 238000009826 distribution Methods 0.000 description 4
- 239000007791 liquid phase Substances 0.000 description 4
- KXDHJXZQYSOELW-UHFFFAOYSA-M Carbamate Chemical compound NC([O-])=O KXDHJXZQYSOELW-UHFFFAOYSA-M 0.000 description 3
- 230000018044 dehydration Effects 0.000 description 3
- 238000006297 dehydration reaction Methods 0.000 description 3
- 239000012071 phase Substances 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000009833 condensation Methods 0.000 description 2
- 230000005494 condensation Effects 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 230000003014 reinforcing effect Effects 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 230000035882 stress Effects 0.000 description 2
- 230000008646 thermal stress Effects 0.000 description 2
- 229910000885 Dual-phase steel Inorganic materials 0.000 description 1
- MKKVKFWHNPAATH-UHFFFAOYSA-N [C].N Chemical compound [C].N MKKVKFWHNPAATH-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000005587 bubbling Effects 0.000 description 1
- 230000002860 competitive effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 210000001503 joint Anatomy 0.000 description 1
- 238000011031 large-scale manufacturing process Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- YWWMFIAQYSERJF-UHFFFAOYSA-N methanamine;urea Chemical compound NC.NC(N)=O YWWMFIAQYSERJF-UHFFFAOYSA-N 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- HDZGCSFEDULWCS-UHFFFAOYSA-N monomethylhydrazine Chemical compound CNN HDZGCSFEDULWCS-UHFFFAOYSA-N 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000001502 supplementing effect Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention discloses a combined urea synthesis reaction device and a system comprising the same, wherein the combined urea synthesis reaction device comprises: the device comprises a methyl ammonium synthesis reaction section, a urea synthesis reaction section and a tail gas washing section; the urea synthesis reaction sections are uniformly and vertically connected to the shell side of the methyl ammonium synthesis reaction section, and the top of each urea synthesis reaction section is provided with a tail gas washing section. The invention solves the problems of large investment in urea high-pressure loop reaction, more key high-pressure equipment, complex process control, large civil engineering investment and the like caused by the fact that the high-pressure equipment of a high-pressure loop is required to be vertically arranged in a high frame. The combined urea synthesis reaction device has the advantages of simple structure, high heat exchange efficiency, low investment and manufacturing cost, convenient arrangement and contribution to equipment manufacturing and device enlargement.
Description
Technical Field
The invention belongs to the field of chemical equipment, and particularly relates to a combined urea synthesis reaction device and a system comprising the same.
Background
The domestic and foreign urea process mainly comprises a Scomion CO 2 stripping process, a ston ammonia extraction process, an Toyo ACES21 process, a Chinese five-ring efficient synthesis process, a low-energy urea process and the like. The competitive process in the market is mainly a five-ring efficient synthesis process in China, a low-energy consumption urea process and a Stomica CO 2 stripping process.
The urea high-pressure loop of the traditional CO 2 stripping process method generally needs four high-pressure devices of a urea synthesis tower, a stripping tower, a high-pressure methylamine condenser and a high-pressure scrubber. The materials of the high-pressure synthesis loop mainly flow by the liquid level difference, and the liquid discharged from the high-pressure scrubber enters the methylamine condenser after being boosted by the liquid level difference and the liquid ammonia ejector and then enters the bottom of the synthesis tower. The liquid from the synthesizing tower flows into the stripping tower by the potential difference. So the high-voltage equipment of the high-voltage loop must be vertically arranged in the high frame, the civil engineering investment is large, and the difficulties of construction installation, operation and maintenance are increased. The high-pressure ring formed by four high-pressure equipment has longer process flow, correspondingly increases the investment cost of the high-pressure equipment and the high-pressure pipeline, and increases unsafe factors of the system.
Disclosure of Invention
The invention aims at overcoming the defects of the prior art and provides a combined urea synthesis reaction device and a system comprising the same.
In order to achieve the above purpose, the present invention adopts the following technical scheme: a combined urea synthesis reaction device, comprising: the device comprises a methyl ammonium synthesis reaction section, a urea synthesis reaction section and a tail gas washing section; the urea synthesis reaction sections are uniformly and vertically connected to the shell side of the methyl ammonium synthesis reaction section, and the top of each urea synthesis reaction section is provided with a tail gas washing section.
Furthermore, the ammonium carbamate synthesis reaction section is of a symmetrical structure, the two ends of the ammonium carbamate synthesis reaction section are provided with heat exchange tubes of double U-shaped tube structures which are symmetrically distributed, the heat exchange tubes are connected with tube plates of the ammonium carbamate synthesis reaction section in a welded mode, and support plates are arranged outside the heat exchange tubes to support the heat exchange tubes.
Further, a steam condensate inlet and a steam condensate outlet are arranged on the pipe box, and the steam condensate is forced to circulate by adopting a steam condensate pump; the bottom of the shell side of the methyl ammonium synthesis reaction section is provided with a first CO 2 gas inlet and a first liquid ammonia inlet, and the upper part of the shell side of the methyl ammonium synthesis reaction section is provided with a second liquid ammonia inlet and a second CO 2 gas inlet.
Further, the number of urea synthesis reaction sections is 3 to 12.
Further, the lower part of the urea synthesis reaction section is provided with a reaction tray, and the upper part is provided with a heat exchange tube bundle; the upper end and the lower end of the heat exchange tube bundle are respectively connected with the tube plates in a welded mode, and the heat exchange tube bundle is supported by the baffle plates.
Further, the upper part of the shell side of the urea synthesis reaction section is provided with a temperature-adjusting water outlet, and the lower part is provided with a temperature-adjusting water inlet; the upper part of the tube side is provided with a urine outlet.
Further, the tail gas washing section comprises a liquid collecting funnel, a packing layer and a central tube, wherein the liquid collecting funnel is arranged at the bottom of the tail gas washing section, the packing layer is arranged above the liquid collecting funnel, the upper part of the central tube is communicated with the bottom of the liquid collecting funnel, the central tube penetrates through the urea synthesis reaction section, and the lower part of the central tube is communicated with the shell side of the methyl ammonium synthesis reaction section.
Further, the top of the tail gas washing section is provided with an inert gas outlet, and the upper part of the tail gas washing section is provided with a low-concentration methyl ammonium liquid inlet.
A urea synthesis system comprises the combined urea synthesis reaction device.
Further, the system also comprises a stripping tower;
The raw materials of liquid ammonia and carbon dioxide enter a shell side of a methyl ammonium synthesis reaction section, and are mixed and reacted in the methyl ammonium synthesis reaction section to generate methylamine and aminomethylamine, and the heat released by the reaction is absorbed by steam condensate of the tube side and gasified to generate low-pressure steam to be taken away;
The reacted gas-liquid two-phase enters the lower part of the urea synthesis reaction section, the urea is dehydrated from bottom to top in the urea synthesis reaction section, the urea solution is discharged from a liquid outlet at the upper part of the urea synthesis reaction section and enters a stripping tower for further stripping, and the gas which is not fully reacted is returned to the methylamine synthesis reaction section after being washed and absorbed by the flowing low-concentration methylamine liquid in the tail gas washing section.
The invention combines a urea synthesizing tower, a high-pressure condenser and a high-pressure scrubber of a traditional urea high-pressure ring into one device. The shell side high-pressure cylinder body of the high-pressure condenser is enlarged, and the three urea synthesis reaction sections and the tail gas washing section are arranged at the upper part of the shell side to play the roles of a urea synthesis tower and a high-pressure washer, so that three devices are integrated, the process flow is greatly simplified, the investment is reduced, the high-pressure system flow is simpler, and the production is safer.
The traditional high-pressure condenser is arranged vertically, and the medium is required to flow smoothly through enough level difference between every two devices, so that the frame is higher and the civil engineering investment is high. The potential difference requirement is greatly reduced, the large-scale device is facilitated, and the civil engineering investment is reduced.
The shell side steam condensate of the methyl ammonium synthesis reaction section is pressurized and conveyed by the condensate pump, so that the flow speed of the condensate in the heat exchange tube is improved, and the heat transfer efficiency is greatly improved. Compared with the traditional natural circulation heat exchange, the heat exchange area of the heat exchange tube is greatly reduced, and the equipment investment is reduced.
The reaction section for synthesizing the methyl ammonium adopts a double U-shaped pipe structure, the pipe bundle can be expanded freely, the problem of thermal stress caused by inconsistent thermal expansion amounts of the pipe and the shell side of the traditional fixed pipe plate type high-pressure methyl ammonium condenser is avoided, an expansion joint is not required to be arranged on equipment, and the risk of stress corrosion of the pipe head can be greatly reduced. The steam condensate absorbs a large amount of heat and is gasified into steam, the steam with fixed pressure cannot absorb heat through the heat exchange tube, and the effective utilization rate is reduced. The double U-shaped pipes are symmetrically arranged, so that the effective heat exchange area and the heat exchange space can be utilized to the greatest extent, the ineffective heat exchange area is greatly reduced, and the large-scale device is facilitated. Meanwhile, the diameter of the tube bundle can be reduced by adopting a double U-shaped tube structure, the tube plate can be made of integral stainless steel or dual-phase steel, and the welding joint of the heat exchange tube and the tube plate can be an inner hole welding butt joint or an angle welding joint.
The liquid ammonia inlet and the CO 2 inlet of the shell pass of the methyl ammonium synthesis reaction section adopt a distributor to uniformly distribute materials in the length direction of the shell pass, and the distributor is an inner extension pipe structure with distribution holes. The liquid ammonia inlet of the shell side and the CO 2 inlet are mixed and then react to generate carbamate and simultaneously emit a large amount of heat, and the released large amount of heat is absorbed by the steam condensate of the tube side and gasified to generate low-pressure steam to be taken away. Simultaneously promotes the continuous reaction of the shell-side liquid ammonia and CO 2 to generate the carbamate. Part of the carbamate is dehydrated in the upper layer of the shell side to generate urea. The two reactions of CO 2 and liquid ammonia to generate methyl ammonium and the dehydration of the methyl ammonium to generate urea are carried out in one device step by step, so that the utilization rate of the device space is improved.
The upper part of the shell side of the methyl ammonium synthesis reaction section is provided with the following advantages with three identical urea synthesis reaction sections and tail gas washing sections through flanges: reducing large openings in the device; eliminating a process flow slow zone and a flow dead zone; the symmetrical design can be used for balancing the load of equipment; the conversion rate of urea synthesis is improved; the top adopts the low concentration circulation to retrieve the methyl ammonium liquid backward flow, improves the consumption rate of material.
The top adopts the washing section can effectively reduce emission tail gas, reduces exhaust emission, improves the conversion rate of material.
The lower part of the urea synthesis reaction section is provided with a plurality of tower plates, the inner space is divided into a plurality of compartments, each compartment is a high-pressure bubbling section, and gas and liquid phases after reaction enter from the bottom and uniformly pass through the tower plates, so that the gas and the liquid ammonia are fully mixed and contacted, and plug flow is realized, the material back mixing phenomenon between the compartments is completely prevented, and the CO 2 conversion rate is effectively improved. And simultaneously, the methyl ammonium continuously dehydrates along with the flowing medium to generate urea.
The upper part of the urea synthesis reaction section is provided with a heat exchange section, a process medium is arranged in the pipe, the methyl ammonium is continuously dehydrated in the pipe to generate urea, the shell side of the urea synthesis reaction section is provided with a temperature-adjusting water inlet, and the temperature of the temperature-adjusting water is increased to take away the heat released by the dehydration of the methyl ammonium. The generated urea methyl ammonium solution enters a stripping tower through a pipeline to be further stripped, and the tail gas after the reaction enters a tail gas washing section through distribution holes on a liquid collecting funnel.
In the tail gas washing section, the low-concentration methyl ammonium solution from the outside passes through a distributor to be continuously absorbed, reacted and washed with the tail gas (a small amount of NH 3、CO2 and inert gas) left after the reaction of the urea synthesis reaction section, so that the conversion rate is improved. The liquid collecting funnel is arranged below the tail gas washing section and is communicated with the central tube of the tube array heat exchanger, and the tail gas directly enters the top of the shell side of the methyl ammonium synthesis reaction section, so that the absorption washing effect is enhanced.
The application has the beneficial effects that: (1) is beneficial to the large-scale production of the device. (2) The device improves heat exchange efficiency, reduces heat exchange area, improves conversion efficiency and is favorable to equipment miniaturization. (3) The two reactions of CO 2 and liquid ammonia to generate methyl ammonium and the dehydration of the methyl ammonium to generate urea are carried out in one device step by step, so that the utilization rate of the device space is improved. (4) The outlet adopts three identical designs of urea synthesis reaction sections and tail gas washing sections, so that the conversion rate of urea synthesis is improved, the top of the gas washing section adopts low-concentration material flow reflux, and the consumption rate of materials is improved. (5) The double U-shaped pipes are symmetrically arranged in the reaction section for synthesizing the methyl ammonium, so that the outer wall of the heat exchange pipe can be guaranteed to the greatest extent to continuously exchange heat, heat generated by the reaction of the shell side CO 2 and the liquid ammonia can be continuously taken away, the production of the methyl ammonium is facilitated, the conversion effective area and the conversion rate are improved, and the ineffective heat exchange area is reduced. The U-shaped tube structure, the tube bank can free expansion, avoids the thermal stress problem that traditional high pressure methylamine condenser tube shell side thermal expansion is inconsistent to produce, and equipment need not to set up the expansion joint, reduces tube head stress corrosion risk. (6) The combined urea synthesis reaction device is a horizontal reactor, the position of a liquid phase outlet is higher, and the liquid phase can directly enter a CO 2 stripping tower through gravity flow without external power supply.
Drawings
FIG. 1 is a schematic structural view of a combined urea synthesis reaction device according to an embodiment.
FIG. 2 is a process flow diagram of an embodiment urea synthesis system.
Reference numerals: 1: a methylamine synthesis reaction section; 1-1: a steam condensate inlet; 1-2: a tube box; 1-3: a tube box separation baffle; 1-4: a vapor and vapor condensate outlet; 1-5: tube box tube sheet, 1-6: u-shaped heat exchange tube; 1-7: a second liquid ammonia inlet; 1-8: a support plate; 1-9: a manhole is inspected; 1-10: shell side of the reaction section for synthesizing methyl ammonium; 1-11: reinforcing rib plates; 1-12: a second CO 2 gas inlet; 1-13: a saddle; 1-14: a first CO 2 gas inlet; 1-15: a CO 2 gas inlet distributor; 1-16: a first liquid ammonia inlet; 1-17: liquid ammonia inlet distributor.
2: A urea synthesis reaction section; 2-1: a flange; 2-2: a reaction tray; 2-3: a lower tube sheet; 2-4: a heat exchange tube bundle; 2-5: urea synthesis reaction section shell side; 2-6: a temperature-regulating water outlet; 2-7: a urine outlet; 2-8: an upper tube sheet; 2-9: a baffle plate; 2-10: temperature control Shui Rukou; 2-11: and (5) welding a lip sealing ring.
3: A tail gas washing section; 3-1: a liquid collection funnel; 3-2: a filler layer; 3-3: an inert gas outlet; 3-4: a low-concentration methyl ammonium liquid inlet; 3-5: a central tube.
4: A reaction device; 5: a stripping column; 6: a high pressure ammonia pump; 7: a CO 2 compressor; 8: a low pressure steam drum.
Detailed Description
In order to enable those skilled in the art to better understand the present application, the following description will make clear and complete descriptions of the technical solutions according to the embodiments of the present application with reference to the accompanying drawings. It will be apparent that the described embodiments are merely some, but not all embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present application without making any inventive effort, shall fall within the scope of the present application.
It is noted that the terms "comprises" and "comprising," and any variations thereof, in the description and claims of the present application and in the foregoing figures, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed or inherent to such process, method, article, or apparatus.
Referring to fig. 1, a combined urea synthesis reaction apparatus includes: a methyl ammonium synthesis reaction section 1, a urea synthesis reaction section 2 and a tail gas washing section 3. The urea synthesis reaction sections are evenly and vertically connected to the shell side of the methyl ammonium synthesis reaction section, and the top of each urea synthesis reaction section is provided with a tail gas washing section. The bottom of the combined urea synthesis reaction device is supported by saddles 1-13.
The ammonium carbamate synthesis reaction section 1 is of a symmetrical structure, two ends of the ammonium carbamate synthesis reaction section are provided with tube boxes 1-2, the ammonium carbamate synthesis reaction section is internally provided with heat exchange tubes 1-6 tube bundles of double U-shaped tube structures which are symmetrically distributed, the heat exchange tubes are welded with a first tube plate 1-5 of the tube boxes, and the heat exchange tubes are externally provided with support plate supports 1-8.
The tube box is provided with a steam condensate inlet 1-1 and a steam and steam condensate outlet 1-4, a first CO 2 gas inlet 1-14 and a first liquid ammonia inlet 1-16 are arranged at the bottom of a shell pass of a forced circulation methylamine synthesis reaction section of steam condensate by adopting a steam condensate pump, and a second liquid ammonia inlet 1-7 and a second CO 2 gas inlet 1-12 are arranged at the upper part of the shell pass. The first CO 2 gas inlet 1-14 outlet is provided with a CO 2 gas inlet distributor 1-15, and the first liquid ammonia inlet 1-16 outlet is provided with a liquid ammonia inlet distributor 1-17. The first inlet of CO 2 and liquid ammonia is the main feed inlet, and the second inlet is the reaction component adjusting inlet.
And an inspection manhole 1-9 is arranged on the shell side 1-10 of the methyl ammonium synthesis reaction section. The tube box 1-2 is provided with a separation baffle 1-3.
The lower part of the urea synthesis reaction section 2 is provided with a reaction tray 2-2, and the upper part is provided with a heat exchange tube bundle 2-4. The upper end and the lower end of the heat exchange tube bundle are respectively connected with the upper tube plate 2-8 and the lower tube plate 2-3 in a welding way, and the heat exchange tube bundle is supported by the baffle plates 2-9.
The upper part of the urea synthesis reaction section shell pass 2-5 is provided with a temperature-regulating water outlet 2-6, and the lower part is provided with a temperature-regulating water inlet 2-10. The upper part of the tube side is provided with a urine outlet 2-7.
The lower part of the urea synthesis reaction section is fixed on the upper part of the methyl ammonium synthesis reaction section through a flange 2-1 and is communicated with the methyl ammonium synthesis reaction section, and a welding lip sealing ring 2-11 is arranged on the flange. The flange is supported by reinforcing rib plates 1-11. The urea synthesis reaction section and the tail gas washing section are directly communicated through welding.
The tail gas washing section 3 comprises a liquid collecting funnel 3-1, a packing layer 3-2 and a central tube 3-5. The liquid collecting funnel is arranged at the bottom of the tail gas washing section, the packing layer is arranged above the liquid collecting funnel, the upper part of the central tube is communicated with the bottom of the liquid collecting funnel, the central tube penetrates through the urea synthesis reaction section, and the lower part of the central tube is communicated with the shell side of the methyl ammonium synthesis reaction section.
The top of the tail gas washing section is provided with an inert gas outlet 3-3, and the upper part is provided with a low-concentration methyl ammonium liquid inlet 3-4.
The urea synthesis system according to fig. 2 comprises a combined urea synthesis reaction device 4 and a stripper 5.
Ammonia from a high-pressure ammonia pump 6 enters from a first liquid ammonia inlet 1-16, uniformly distributed by a liquid ammonia inlet distributor 1-17, enters into a shell side 1-10 of a methyl ammonium synthesis reaction section, CO 2 from a CO 2 compressor 7 enters from a first CO 2 gas inlet 1-14, The mixture is evenly distributed by a CO 2 gas inlet distributor 1-15 and then enters a shell pass 1-10 of a methyl ammonium synthesis reaction section. CO 2 gas and liquid ammonia are mixed and reacted in the shell pass 1-10 of the reaction section for synthesizing the methyl ammonium to generate the methyl ammonium, a large amount of heat is released, the released large amount of heat is absorbed by the steam condensate of the tube pass and gasified to generate low-pressure steam to be taken away, and simultaneously, the shell pass liquid ammonia and CO 2 are promoted to continuously react to generate the amino methyl ammonium. And (3) partially dehydrating the ammonium carbamate after absorbing heat at the upper part of the shell pass 1-10 of the ammonium carbamate synthesis reaction section to generate urea, respectively supplementing a certain amount of liquid ammonia and CO 2 (from a second CO 2 gas inlet and a second liquid ammonia inlet) at the upper part of the shell pass 1-10 of the ammonium carbamate synthesis reaction section, promoting the condensation of the ammonium carbamate, and controlling the ammonia-carbon ratio in the reactor. The reacted gas-liquid two-phase enters the lower part of the urea synthesis reaction section 2, the methyl ammonium liquid is baffled in a high-efficiency tray, the gas is collected in the tray and flows upwards along the distribution holes of the tray, the methyl ammonium is generated by reaction between the trays, and part of the methyl ammonium is hydrolyzed to generate urea. The gas-liquid two-phase continues to flow upwards in the 2 urea synthesis reaction section, enters into a 2-4 heat exchange tube bundle, is carried along with the heat of reaction by a temperature-adjusting water, and continues to carry out the reaction of generating urea by dehydrating methyl ammonium, and finally the urea solution generated by the reaction flows out from a urine outlet 2-7 and enters into a CO 2 stripping tower for further stripping. The flash steam after steam stripping enters the bottom of the urea synthesis reactor, and the liquid-phase urea product is decompressed to obtain a urea synthesis high-pressure ring. The gas which is not reacted completely enters the packing layer 3-2 upwards through the distribution holes on the liquid collecting funnel 3-1, flows reversely with the methyl ammonium liquid entering from the low-concentration methyl ammonium liquid inlet 3-4, and returns to the upper part of the shell side 1-10 of the methyl ammonium synthesis reaction section to continue to participate in the reaction after NH 3 and CO 2 in the gas are absorbed by the methyl ammonium liquid through the central tube 3-5. Inert gas which does not participate in the reaction is discharged from the inert gas outlet 3-3.
The U-shaped heat exchange tube 1-6 bundles of tube side steam condensate of the methyl ammonium synthesis reaction section 1 enters the tube box 1-2 through the steam condensate inlet 1-1 and then uniformly enters the U-shaped heat exchange tube to take away heat generated by condensation of shell side methyl ammonium, the steam condensate is heated to generate steam, and the steam flows out from the steam and steam condensate outlet 1-4 and enters the low-pressure steam drum 8.
The above description of the present invention is further illustrated in detail and should not be taken as limiting the practice of the present invention. It is within the scope of the present invention for those skilled in the art to make simple deductions or substitutions without departing from the concept of the present invention.
Claims (10)
1. A combined urea synthesis reaction device, characterized by comprising: the device comprises a methyl ammonium synthesis reaction section, a urea synthesis reaction section and a tail gas washing section; the urea synthesis reaction sections are uniformly and vertically connected to the shell side of the methyl ammonium synthesis reaction section, and the top of each urea synthesis reaction section is provided with a tail gas washing section.
2. The combined urea synthesis reaction device according to claim 1, characterized in that: the ammonium carbamate synthesis reaction section is of a symmetrical structure, the two ends of the ammonium carbamate synthesis reaction section are provided with heat exchange tubes of double U-shaped tube structures which are symmetrically distributed, the heat exchange tubes are connected with tube plates of the ammonium carbamate synthesis reaction section in a welded mode, and supporting plates are arranged outside the heat exchange tubes to support the heat exchange tubes.
3. The combined urea synthesis reaction device according to claim 2, characterized in that: the pipe box is provided with a steam condensate inlet and a steam condensate outlet, and the steam condensate is forced to circulate by adopting a steam condensate pump; the bottom of the shell side of the methyl ammonium synthesis reaction section is provided with a first CO 2 gas inlet and a first liquid ammonia inlet, and the upper part of the shell side of the methyl ammonium synthesis reaction section is provided with a second liquid ammonia inlet and a second CO 2 gas inlet.
4. The combined urea synthesis reaction device according to claim 1, characterized in that: the number of the urea synthesis reaction sections is 3-12.
5. The combined urea synthesis reaction device according to claim 1, characterized in that: the lower part of the urea synthesis reaction section is provided with a reaction tray, and the upper part of the urea synthesis reaction section is provided with a heat exchange tube bundle; the upper end and the lower end of the heat exchange tube bundle are respectively connected with the tube plates in a welded mode, and the heat exchange tube bundle is supported by the baffle plates.
6. The combined urea synthesis reaction device according to claim 1, characterized in that: the upper part of the shell side of the urea synthesis reaction section is provided with a temperature-regulating water outlet, the lower part is provided with a temperature-adjusting water inlet; the upper part of the tube side is provided with a urine outlet.
7. The combined urea synthesis reaction device according to claim 1, characterized in that: the tail gas washing section comprises a liquid collecting funnel, a packing layer and a central tube, wherein the liquid collecting funnel is arranged at the bottom of the tail gas washing section, the packing layer is arranged above the liquid collecting funnel, the upper part of the central tube is communicated with the bottom of the liquid collecting funnel, the central tube penetrates through the urea synthesis reaction section, and the lower part of the central tube is communicated with the shell side of the methyl ammonium synthesis reaction section.
8. The combined urea synthesis reaction device according to claim 1, characterized in that: the top of the tail gas washing section is provided with an inert gas outlet, and the upper part of the tail gas washing section is provided with a low-concentration methyl ammonium liquid inlet.
9. A urea synthesis system, characterized by: a combined urea synthesis reaction device comprising any one of claims 1 to 8.
10. Urea synthesis system according to claim 9, characterized in that: the system further comprises a stripper;
The raw materials of liquid ammonia and carbon dioxide enter a shell side of a methyl ammonium synthesis reaction section, and are mixed and reacted in the methyl ammonium synthesis reaction section to generate methylamine and aminomethylamine, and the heat released by the reaction is absorbed by steam condensate of the tube side and gasified to generate low-pressure steam to be taken away;
The reacted gas-liquid two-phase enters the lower part of the urea synthesis reaction section, the urea is dehydrated from bottom to top in the urea synthesis reaction section, the urea solution is discharged from a liquid outlet at the upper part of the urea synthesis reaction section and enters a stripping tower for further stripping, and the gas which is not fully reacted is returned to the methylamine synthesis reaction section after being washed and absorbed by the flowing low-concentration methylamine liquid in the tail gas washing section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410437545.2A CN118743972A (en) | 2024-04-12 | 2024-04-12 | Combined urea synthesis reaction device and system comprising same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410437545.2A CN118743972A (en) | 2024-04-12 | 2024-04-12 | Combined urea synthesis reaction device and system comprising same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN118743972A true CN118743972A (en) | 2024-10-08 |
Family
ID=92922221
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410437545.2A Pending CN118743972A (en) | 2024-04-12 | 2024-04-12 | Combined urea synthesis reaction device and system comprising same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN118743972A (en) |
-
2024
- 2024-04-12 CN CN202410437545.2A patent/CN118743972A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102888252B (en) | Saturation tower/isothermal furnace series/heat isolation furnace CO transformation technology | |
| WO2016045585A1 (en) | Large reactor and device and process thereof | |
| CN102888253B (en) | Low-moisture low-variable serial saturation tower thermal CO transformation technology | |
| CN102887480B (en) | CO shift technique by connecting isothermal shift and thermal insulation shift in series | |
| CN1152738C (en) | Reactor, in particular for exothermic reactions | |
| CN102886230B (en) | CO (carbon monoxide) conversion process adopting tandem isothermal furnaces of saturation tower | |
| CN102887481B (en) | Low water-gas ratio pre-conversion constant-temperature CO conversion technology | |
| CN102895922B (en) | Industrial plate type reactor for preparing glycol by hydrogenating oxalate or preparing alcohol by hydrogenating ester | |
| CN102766021B (en) | Production system and production method for continuously producing ethanol by ethyl acetate through using hydrogenation | |
| CN102850183B (en) | Methanol synthesis system and method | |
| CN102410518B (en) | Low-grade heat energy recycling method for liquid urea washing tower | |
| CN103240036B (en) | A kind of heat transfer reactor of Anti-temperature difference stress and combinations thereof device and application | |
| CN102872767B (en) | Industrialized plate type reactor for carbonylating and coupling to synthesize ester | |
| CN113091338B (en) | Reaction heat recycling system in formaldehyde production | |
| CN118743972A (en) | Combined urea synthesis reaction device and system comprising same | |
| CN202876771U (en) | Industrialized plate type reactor for preparing glycol by oxalate hydrogenation or alcohol by ester hydrogenation | |
| CN212119062U (en) | Nitric acid recovery unit in adipic acid production | |
| CN106610237A (en) | Novel carbon dioxide cooling device | |
| CN216909762U (en) | Carbon capture recycling system is administered to two carbons | |
| CN106732209B (en) | Boiling type isothermal reactor and isothermal control process | |
| CN104651220A (en) | Solar warming system for multi-phase biogas digester | |
| CN203108234U (en) | Hybrid evaporimeter | |
| CN116496225A (en) | Melamine production method and equipment | |
| CN201350404Y (en) | High pressure tubular full-condensation reactor | |
| CN111848398A (en) | Dehydrogenation reaction device for synthesizing methyl formate and process thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |